Effect of stacking fault energy on mechanical properties and annealing behavior of brasses

Abstract

The effect of stacking fault energy (SFE) on mechanical properties and annealing behavior of brasses was studied in Cu–20Zn alloy (SFE ∼18 mJ/m2) and Cu–20Zn–1.2Si alloy (SFE ∼9 mJ/m2) as well as Cu–20Zn–1.9Si alloy (SFE ∼6 mJ/m2) alloy. These brasses have been rolled at room temperature up to different thickness reductions. The significant improvement of strength in Cu–20Zn–1.9Si alloy is attributed to the formation of fine grains and high densities of dislocations and deformation twins by decreasing the SFE. Thermal stability is enhanced due to the reductions of dislocation mobility and grain boundaries migration during annealing by a decrease in SFE and addition of Si. High fractions of the {236} 〈385〉 Brass–R and (55; 30; 0) in Cu–20Zn–1.9Si alloy with lower SFE should be ascribed to the substantial Brass texture in deformed microstructures. Fine grains, deformation twins and abundant annealing twins were introduced into Cu–20Zn–1.9Si alloy by decreasing the SFE, resulting in superior strength–ductility combination.